Lath and wall construction embodying same



Sept. 3, 1935. s. A. SWANSON 2,013,255

LATE AND WALL CONSTRUCTION EMBODYING SAME 7 Filed May 2, 1933 Sven flwszdan son W WFMW Patented Sept. 3, 1935 UNITED STATES PATENT OFFICE LATH AND WALL CONSTRUCTION EMBODYING SAME 1 Claim.

This invention relates to building construction and particularly to plastered ceilings and walls.

It has for its general object the provision of an improved lath.

One of the more specific objects of the invention is to provide a lath construction in which valleys with bevelled sides are formed between adjacent laths for increasing the amount of plastering retained between the laths, thus improving the support afforded to the plaster between laths in vertical walls, the bevel being of such obliquity as to constitute a sticking taper and avoiding such excessive steepness as would cause the plaster to tend to slide down the surface of the bevel through its sheer weight.

Another object of the invention is to provide a lath construction which will condense the plaster in the keyways, expanding in both directions at the back of the keyway.

A further object of the invention is to provide a lath that will not warp, that will become more quickly and uniformly saturated at the sides of the keyway than the ordinary lath, and which will be light, inexpensive and easy to apply.

Other objects of the invention will appear as the following description of a preferred and practical embodiment thereof proceeds.

In the drawing which accompanies and forms a part of the following specification and throughout the several figures of which the same characters of reference have been employed to denote identical parts:

Figure 1 is a horizontal section through a plastered ceiling, illustrating the invention;

Figure 2 is a vertical section through a side wall construction;

Figure 3 is optionally, a plan view of the ceiling or a front elevation of the side wall intermediate parts being broken away;

Figure 4 is a cross section on an enlarged scale through a single lath; and

Figure 5 is a perspective view of a single lath.

Referring now in detail to the several figures, the numeral I represents a piece of studding to which as illustrated in Figures 1 and 2, a plurality of laths 2 are secured by nails 3. A layer of plaster is indicated at 4 having a finish coat 5, although the latter in no wise is involved in the present invention.

Referring to Figure 4, it will be noted that the lath 2 has parallel front and back sides 6 and 1 and bevelled edges 8 and 9. With the laths arranged in customary manner on the ceiling as shown in Figure 1 or side wall as illustrated in Figure 2, the bevelled edges of adjacent laths form the sides of valleys ID, the open bottoms of which form keyways for the extrusion of the plaster to the opposite side of the laths. Under pressure of the trowel the plaster by a wedging action is condensed into the bottoms of the valleys so that it expands immediately it is freed from the pressure on the opposite sides of the keyways, completely filling the latter and extending equally on both sides thereof in the case of the ceiling, and in the case of the side wall spreading a slight distance beyond the edge of the upper lath and of course, depending for a considerable distance from the edge of the lower lath.

The condensing action of the bevelled edges of adjacent laths causes the plaster within said valleys and especially in the keyways to become particularly dense and strong. Furthermore, in the side Wall construction as shown in Figure 2, the densified plaster within the valleys seats upon the upper bevelled edge of the lower laths of a pair supporting the plaster and distributing its weight equally over the entire height of the wall. The densified portion of plaster which interdigitates with the valleys between the laths resists to an unusual degree any tendency to break off from the outlying layer of plaster, not only through inherent strength acquired through its densification, but because of the width of the interdigitating portions due to the inclined shape of the walls constituting the keyway.

The present construction as contrasted with the usual arrangement in which the end faces of the laths are perpendicular to their front and back faces presents several advantages. In the older construction in which the sides of the keyways are bevelled, the plaster is not densified when pressed through by the trowel, but begins to flow just as soon as it enters the keyway so that at the point of extrusion on the opposite side of the wall, it lies in contact only with the lower edge of the keyway affording an extremely weak means of support. Furthermore, the narrowness of the layer of plaster occupying the keyway presents but little strength so that it very readily may break off from the layer of plaster on the face of the wall. The inconsiderableness of its mass also permits it to dry out faster than the outlying layer of plaster, further impairing its strength.

In the construction of the present invention, the feather edge formed by the intersection of the bevelled edges of the laths with the back surfaces thereof become more uniformly saturated with moisture than the more massive portions of the lath thus ensuring an intimate bond between the lath and the plaster at the thinnest portion of the plaster key where such bond is most needed.

In view of the fact that the lateral portions of the lath do become uniformly saturated, tendency of the lath to warp is minimized.

It is preferred to nail the lath to the studding precisely in the middle so as to completely balance those stresses which might cause warping.

The bevelled edges of the lath may taper from the back surface at any desired angle, up to 45", but a slope greater than 45 will defeat one of the main purposes of the present invention which is to cause the lath toafford aseat or support for the plaster immediately overlying it. With an inclination of more than 45, there will be a tendency for the plaster to slide forwardly along the bevelled surface through its sheer weight.

While I have in the above description disclosed what I believe to be a preferred and practical embodiment ofmy invention, it is to be understood that the details of construction are merely by way of example and not to be construed as limiting the scope of the invention as claimed.

What I claim is:

Wall construction comprising a plurality of laths laid parallel and spaced, each lath having parallel front'and back faces and bevelled edges sloping toward the front and forming sharp edges with the front face, the bevelled edges of adjacent laths forming the sides of valleys convergent toward keyways formed by'the spacing of said laths, a plaster layer facing said plurality of laths in adherent relation thereto and filling said valleysythe plaster in said valleys being densified bywedge action under the pressure of the trowel employed in applying the plaster, the upper bevelled edge of each lath sloping at an angle not exceeding 45 whereby to 'aiford support for the plaster adherent thereto.

SVEN A. SWANSON. 

